Production line for products of prestressed concrete or of reinforced concrete

ABSTRACT

The production line includes a rotary hall, which itself transports the moulds, in front of installations for cleaning and oiling, positioning and stressing, concreting, heat treatment, demoulding and removal, and a metallic structure, which passes through the hall thereby supporting all the installations in the best working positions and various enclosures. The rotation of the hall is effected stepwise or in continuous movement, on rollers, mounted on the outside.

llnited States Patent 1 Borcoman [4 1 May 8, 1973 [541 PRODUCTION LINE FOR PRODUCTS OF PRESTRESSED CONCRETE OR OF REINFORCED CONCRETE [76] Inventor: Mircea Borcoman, 53,55 Bd de la Villette, Paris, France [22] Filed: Oct. 7, 1970 [21] Appl. No.: 79,187

[30] Foreign Application Priority Data Oct. 10, 1969 France ..6934660 [52] U.S. Cl. ..425/111, 25/132, 425/439, 425/99 [51] Int. Cl ..B28b 5/12, B28b 23/06 [58] Field of Search ..25/2, 118 T, 75, 25/80, 132, 41 F, 41 H;249/137, 139;

[5 6] References Cited UNITED STATES PATENTS 1,599,151 9/1926 Vought ..25/41 H X 2,317,574 4/1943 Williams ..25/41 H 3,477,108 11/1969 Stokes ..25/75 X 3,003,188 10/1961 Weiss 25/41 H X 1,659,987 2/1928 Benson et al.. .....25/41 H 3,568,272 3/1971 Zmania ..25/2 3,577,610 5/1971 Margolm ...25/2 3,305,907 2/1967 Baker ..25/2

FOREIGN PATENTS OR APPLICATIONS 1,029,377 5/1966 Great Britain ..25/2

Primary Examiner-J. Spencer Overholser Assistant Examiner-Ben D. Tobor Attorney-Larson, Taylor and Hinds [57] ABSTRACT The production line includes a rotary hall, which itself transports the moulds, in front of installations for cleaning and oiling, positioning and stressing, concreting, heat treatment, demoulding and removal, and a metallic structure, which passes through the hall thereby supporting all the installations in the best working positions and various enclosures. The rotation of the hall is effected stepwise or in continuous movement, on rollers, mounted on the outside.

7 Claims, 3 Drawing Figures PATENTED HAY 1m SHEET 1 BF 3 PRODUCTION LINE FOR PRODUCTS OF PRESTRESSED CONCRETE OR OF REINFORCED CONCRETE The present invention relates to a method and to a production line for products of prestressed concrete and of reinforced concrete as for example: beams, girdles, rib-stalls, flanks, cross-pieces, closure parts, slabs, semi-circular channels, stakes, etc.

There are many methods and production lines for such products, which can be classified into five main groups: ground level, separate stations conveyor belts, vertical flow and rotary body. In ground level methods, moulds are mounted at points fixed to the horizontal, so that the technological processes of cleaning, of oiling, of mounting cores, of concreting, of finishing and of demoulding, are carried out over the whole surface with long distances of transportation, with numerous intersections of flows and losses of time between the operations, whilst heat treatment is done with difficulties of sealing and with an increased amount of steam. The production lines formed according to these methods have a very long manufacturing cycle, a considerable consumption of energy and require high use of labor and of surface construction. The methods with separated stations, according to which the moulds are moved by means of lifting apparatus, bring about a reduction of the surface occupied and of the number of flow intersections, but the difficulties persist as regards effecting heat treatments and use of labor. Moreover, the lines produced for the application of these methods have an increased consumption of energy because the transportation of the moulds, both empty and filled with concrete, in the manufacturing circuit, is carried out by means of lifting apparatus. The methods by conveyor, according to which the moulds pass, in continuous movement or stepwise, in front of various specialized working stations, offer certain advantages with respect to the first methods, especially as regards reduction of handling, cost of production and risks of accidents. However, these methods have limited possibilities of application (especially for manufacture of products of prestressed concrete) and a further increased consumption of energy. The production of lines in closed chain" with complex automation is expensive and difficult to obtain, and it results that the majority of the conveyor lines have their cycle interrupted and a degree of automation which does not satisfy present requirements. In using vertical flow methods, the surface occupied and the total cycle time of manufacture are reduced, but the consumption of energy and handling is further increased. In certain cases, lines effected according to these methods are expensive in capital costs and have a restricted field of application. In the methods with a rotating body, moulds mounted on the outer surface of a cylindrical body are transported in the manufacturing circuit by the rotation, in stepwise or in continuous motion of the latter. The various working stations placed all around the body moulds assembly have their operation synchronized with its rotation. In this way, these methods permit production lines having a very high degree of automation and a minimum consumption of energy. However, they do not exclude the possibilities of reduction of the surface constructed and of investment costs.

The method according to the invention enables the drawbacks of the known methods to be avoided, by using a rotary hall which carries itself, the moulds placed on its inner surface, in front of the work stations, mounted in the most advantageous positions on a metallic structure which passes through the hall, so that the whole of the inner space of the hall is available, including the surface of the walls, for the organization of the technological processes, and of the workshops, of the depots, of the dressing-rooms, etc. The method and the production line may be effected in three main variations according to the general technological flow: one, with rotation in continuous movement, having moulds fixed in a circular contour; and two and three, with stepwise rotation, having the moulds attached in a polygonal contour, either in a fixed manner when the concreting is effected on the inside, or in a dismantable manner when the concreting is done outside the rotary hall.

In order that the invention may be more fully understood, one example of an embodiment of the method and of the production line according to the invention is described below, purely by way of illustrative but non-limiting example, corresponding to the second variation of the general technological flow, with reference to the accompanying drawings, in which:

FIG. I is a cross-section in a vertical plane along the line 1-1 of FIG. 2, of one embodiment according to the invention of a production line for the manufacture of prestressed concrete products;

FIG. 2 is a longitudinal section in a vertical plane along the line IIII FIG. I, of the embodiment of FIG. 1; and

FIG. 3 shows a detail of the strengthening structure and of the anchoring parts along the line IIIIII of FIG. 1.

According to the invention, the technological line comprises: a rotary hall for the moulds, a metallic structure which passes through the hall, installations for cleaning N, oiling l-I, positioning MP, tensioning MT, concreting B, heat treatment TT, demoulding D, evacuation E, and enclosures S for: office, laboratory, workshop for cores and maintenance, a depot for spools and dressing-rooms.

The rotary hall has three distinct functions: of shelter, of transportation of the moulds in the manufacturing cycle and of support for the forces resulting from the tensioning. To fulfill these functions, it is constituted of a strengthening structure (provided with anchoring parts) with a heat insulating layer, with an outer envelope and with devices for support and for rotation. The strengthening structure comprises: reinforced rings 1, assembled by means of splints 2, tubes 3, rendered rigid wind-bracings 4, and anchoring means 5, pinned to the heads of the tubes 3 by means of mortises 6, tenons 7, and threaded tie-rods 8. The heat insulating layer is effected with panels 9, fixed between the bottom of the moulds and the strengthening structure. For the outer sheltering envelope, use is made of curved plates 10, of sheet metal or of plastics material, mounted on fixing tie-rods to the anchoring beams. The support of the hall is effected by means of two collars 111 and four rollers 12, fastened on the metallic frames 13. The rotation of the hall is effected either by the rollers themselves, or by another conventional mechanism. The rotary hall can itself be constructed, in certain cases, of reinforced or prestressed concrete.

The moulds are assembled in rigid batteries 14, provided with heating jackets 15, which are placed by means of elastic supports 16, on the inner surface of the rings 1. When the line is effected according to the third variation of the method, the batteries are mounted detachably with respect to the hall, to be manoeuvrable at the concreting station, which in this case, is placed outside the hall.

The metallic structure which passes through the hall comprises: a strengthening beam 17, provided with a support apparatus 18, with three stages of platforms 19, on which the installations are organized, the appended enclosures and the spaces for circulation, a heat insulating screen 20, which protects the heating zone, two front walls of glass 21, and cylindrical walls 22, provided with elastic curtains 23, which effect the connection with the rotary hall.

The various installations are mounted on the metallic structure in the most advantageous positions for their operation. The cleaning and the oiling of the moulds are effected in a zone N and H where the moulds are a little inclined to facilitate the flow of the mixtures used. The respective installations are of a special model with jet devices 24, which aspirate the mixtures from the gutters 25, and eject them on the moulds. The excess of mixtures (water with sand for cleaning and oil for oiling) is recovered in gutters and an inner receiver. These devices are fixed on independent carriages 26, which are moved automatically along the moulds by being each provided with a movable system of compressed air 27. The positioning of the wires 28, or of the strands, is done by the usual means or by means of special circuits provided with spools 29 (FIG. 2), moving devices 30, guide parts 31, and aspirating jacks 32, which ensure the locking of the passive head with a considerable reduction of handling.

To tension the buttonned wires (which have, at each end a swelling) with a minimal loss of steel wire, there is used a device enabling, on one hand, the giving to the wires, at rest, a minimal length such that one of the ends of the wires is located inside the moulds and, on the other hand, to exercise, from the inside of the moulds, a traction on the said end until the introduction, by elongation of the wire, outside the mould. The loss of steel wire is thus reduced substantially on the elongation taken by the wires on their tensioning. The above-said device for tensioning the buttonned wires, inside the moulds, one by one or in a group; comprises claws 33, provided with rods 34, which pass through the anchoring plates 35, on which they are locked by means of shells 36, or by other means. The tensioning is effected with ajack 37, and a hydraulic pump 38, of the usual type. The anchoring plates have a simple fixing system, which facilitates their changing, as a function of the product, or their dismounting when it relates to the manufacture in carrying moulds, or manufacture of products of reinforced concrete. The concreting is done in the lower portion B, according to the variation of technological flow adopted. In the accompanying case illustrated, there is used a carriage provided with a distributing hopper 39, with a vibro-finishing plate with a pusher front end 40 with vibrators 41, springs 42, and with two guide-wings for the concrete 43. For the other variations, the concreting installations are of the usual type. The treatment of the concrete is effected by heating by means of a system which sends steam into the jackets of the moulds and a system 44, which ensures a saturation humidity between the free surface of the concrete and the fixed screen 20. The demoulding of the elements is effected as a function of their shape and especially of the position of their cores. For the case of elements which can be in all the positions, the wires are cut and the elements are lowered on a customary removal chain. For elements which must be manipulated in the flow position, use is made of an installation which comprises a beam 45, provided with suction plates 46, with two support collars 47, with two head shafts 48, and a manipulating device provided with two hydraulic cylinders 49, with two circular bearings 50, and with two racks 51. This installation effects automatically the extraction, the lowering, the reversal and the positioning in piles or in containers, of the products. The removal of the products is done either by the usual means, or by means of a conveyor belt which has two guides 52, two chains 53 and bars 54, arranged as a function of the range of support and provided with rubber parts 55, a rollers 56. The various installations described are connected with a central control panel 57, placed on the upper platform. The production line is provided in certain cases with a ventilating installation.

The production line, according to the invention, may be used for the manufacture of prestressed concrete and of reinforced concrete elements as for example: slabs, preslabs, girders, electrical posts, props, stakes, railway sleepers; longitudinal members, espaliers, flanks, pileplanks, closure parts, etc. In following the method, installations for the execution of similar technological processes can be constructed, for other industries.

What I claim is:

1. Production line for the manufacture in moulds of products of prestressed concrete, reinforced concrete or the like, comprising:

a rotary means adapted to support said moulds and rotate them through a rotary path, said rotary means comprising a rotary hall, wherein the moulds line the lateral surface of said hall;

a plurality of work stations positioned around said rotary path, said plurality of work stations including installations for cleaning, oiling, positioning, prestressing, concreting, heat treating, de -m oulding and removing;

means for operationally synchronizing said work stations with rotation of the rotary means;

and support means for said work stations passing through the rotary means, said support means comprising a metallic structure passing through the hall, supporting said installations, and including a front enclosing member.

2. Production line according to claim 1, wherein the rotary hall is constituted by a strengthening framework provided with anchoring parts, by a heat insulating layer, by an envelope, mountedon tie-rods and by support and rotation devices, adapted to effect three distinct functions: of shelter, of transportation of the moulds in the manufacturing cycle and of support for forces resulting from the stressing.

3. Production line according to claim 2, wherein the strengthening structure of the rotary hall is formed of strongly reinforced rings, assembled by splints, of tubes, made rigid by wind-bracings and of anchoring beams, pinned to the heads of the tubes by means of mortises, by tenons and by tie-rods.

4. Production line according to claim 1, in which wires having enlarged ends are used, wherein means of prestressing button-ended wires within the moulds is constituted by claws, by rods and by anchoring plates, provided with locking shells so that, on the final elongation of the wires, the claws reach the end of the moulds,

, thereby ensuring considerable economy of hard steel thereby ensuring considerable economy of hard steel and automatic closure of the moulds.

6. Production line according to claim 3, in which wires having enlarged ends are used, wherein means of prestressing button-ended wires within the moulds is constituted by claws, by rods and by anchoring plates, provided with locking shells so that, on the final elongation of the wires, the claws reach the end of the moulds, thereby ensuring considerable economy of hard steel and automatic closure of the moulds.

7. Production line according to claim 1, wherein the demoulding installations include a cylindrical beam provided with suction plates, with two support collars, with two hinged shafts, and a handling device provided with two hydraulic cylinders, with two circular bearings and two racks, so that it automatically executes the extraction, the lowering, the reversal and the placing of the products in stacks or in containers. 

1. Production line for the manufacture in moulds of products of prestressed concrete, reinforced concrete or the like, comprising: a rotary means adapted to support said moulds and rotate them through a rotary path, said rotary means comprising a rotary hall, wherein the moulds line the lateral surface of said hall; a plurality of work stations positioned around said rotary path, said plurality of work stations including installations for cleaning, oiling, positioning, prestressing, concreting, heat treating, de-moulding and removing; means for operationally synchronizing said work stations with rotation of the rotary means; and support means for said work stations passing through the rotary means, said support means comprising a metallic structure passing through the hall, supporting said installations, and including a front enclosing member.
 2. Production line according to claim 1, wherein the rotary hall is constituted by a strengthening framework provided with anchoring parts, by a heat insulating layer, by an envelope, mounted on tie-rods and by support and rotation devices, adapted to effect three distinct functions: of shelter, of transportation of the moulds in the manufacturing cycle and of support for forces resulting from the stressing.
 3. Production line according to claim 2, wherein the strengthening structure of the rotary hall is formed of strongly reinforced rings, assembled by splints, of tubes, made rigid by wind-bracings and of anchoring beams, pinned to the heads of the tubes by means of mortises, by tenons and by tie-rods.
 4. Production line according to claim 1, in which wires having enlarged ends are used, wherein means of prestressing button-ended wires within the moulds is constituted by claws, by rods and by anchoring plates, provided with locking shells so that, on the final elongation of the wires, the claws reach the end of the moulds, thereby ensuring considerable economy of hard steel and automatic closure of the moulds.
 5. Production line according to claim 2, in which wires having enlarged ends are used, wherein means of prestressing button-ended wires within the moulds is constituted by claws, by rods and by anchoring plates, provided with locking shells so that, on the final elongation of the wires, the claws reach the end of the moulds, thereby ensuring considerable economy of hard steel and automatic closure of the moulds.
 6. Production line according to claim 3, in which wires having enlarged ends are used, wherein means of prestressing button-ended wires within the moulds is constituted by claws, by rods and by anchoring plates, provided with locking shells so that, on the final elongation of the wires, the claws reach Pg,11 the end of the moulds, thereby ensuring considerable economy of hard steel and automatic closure of the moulds.
 7. Production line according to claim 1, wherein the demoulding installations include a cylindrical beam provided with suction plates, with two support collars, with two hinged shafts, and a handling device provided with two hydraulic cylinders, with two circular bearings and two racks, so that it automatically executes the extraction, the lowering, the reversal and the placing of the products in stacks or in containers. 